Lining for tube-mills.



. JENSEN LINING FOR TUBE MILLS.

APPLICATION FILED APR.21. I915.

Patented J an. 14, 1919.

2 SHEETS-SHEET I.

wlmessgs AWE/mm A. V. JENSEN.

LlNlNG FOR TUBE MILLS.

APPLICATION HLED APR.21.1915.

1,291,008. Patented Jan. 14, 1919.

2 SHEETS-SHEET 2. .2... 1 T I IIIII v ATTORNEY UNITED sTATEs PATENToEEIoE.

ALEXANDER V. JENSEN, OF DEVILS SLIDE, UTAH, ASSIGNOR T AMERICAN MANGA- NESE STEELE COMPANY, OF AUGUSTA, MAINE,

A CORPORATION OF MAINE.

LINING FOR TUBE-MILLS.

1,291,o os.

To all whom it, may concern:

Be i known that I, ALEXANDER V. JENSEN,

i1 a s'ubjectof .His ,Majesty. the King of Deni whiclitlie followingis aspecification.

This invention, ,relates to a lining for grindingmills, the object.being to provide a, ampunt of agitation .to the mill contents,

resulting in, the v eiiicient' grind-ing thereof-r It'hasbecome wellknown inthe artz'to" which my invention relates that the grindingzactionis due to the local-motion. and agi tation ofhthe grinding balls orcylpebs; This local movement of-the balls or cylpebsv causes thecontents ,of the mill to be ground I therebetween. Any, sliding actionof the contents of the mill with reference to thelining plates or themill shell, causes excesmill.

sive wear upon the lining plates, and prevents the local agitation andmovement of" the balls and cylpebs one with relation to the other, sothat sliding in the grinding mill takes place at the expense of thelining plates and prevents the proper grinding of the mill contents. Inorder to overcome this sliding of the mill contents, it has heretoforebeen customary to form the lining plates of various shapes and forms andto provide bars or ribs extending longitudinally of the The liningplates were of a haphazard configuration, some being provided withsteps, others with sharply slanting peaked sides, while others were ofa-waved configuration. Such. haphazard configuration did not, however,as will be hereinafter more apparent, produce the maximum local movementof the balls or cylpebs, and consequently the maximum grinding actionwas not obtained. 7

It is accordingly an object of my invention to rovide a lining plate thecurvature of which follows certain definite and fixed mathematical andgeometrical laws, whereby sliding is' greatly reduced; whereby themaximum local movement and rotation of the balls andcylpebs takes place,and whereby the maximum grinding efliciency is obtained. To the aboveend, I have formed Specification of Letters Patent.

a lining whichn will. impart av maximum.

Patented Jan. 14, 1919.

Application filed April 21, 1915. Serial No. 22,732.

my lining from a plurality of lining plates which collectively provide awave-like or undulatory working surface for the interior of the millcasing; the cross-sections'of the individual plates upon planestransverse to the axis of the casing being in the form of i trochoidalcurves, or, more'strictly speaking, the working surfaces of the severalindividual plates being such. that they appear in cross-section astrochoidal curves.

I have also found that, by forming adjacent lining istics, are ofdifferent wave lengths and amplates so'that adjoining portlonsthereofalthough of similar character-' the mill to take up, certain'formations'is" prevented, the local agitation and rotation of theingredients is provided for, and a breaking over of the ingredients'ofthe mill, similar to the surf of ocean waves, is caused to take place.

Other objects and advantages will appear" as the description proceeds,wherein it is to be understood that changes in the precise embodiment ofthe invention can be made within the scope of what is claimed withoutdeparting from the spirit of the invention.

The preferred embodiment of my invention is disclosed in theaccompanying drawings, wherein Figure 1 is aview in end section of agrinding mill equipped with a lining embodying the characteristicfeatures of my invention; I

Fig. 2 is a similar, but enlarged, view of a portion of the foregoing,illustrating a lining plate mathematically curved to obtain the maximumrotation and agitation of the mill contents and entirely eliminatingslids;

Fig. 3 is a sectional view of a lining plate disclosing the reinforcingribs which are formed upon the under or non-working side thereof;

Fig. 4 is a view in the lining plates;

Fig. 5 is a view in end section of a grinding mill, equipped with asomewhat modified form of lining, the modification largely residing inthe manner in which the several lining plates are held in position;

Fig. 6 is a view in perspective of one of perspective of one of theholding members, by means of which the lining plates are held in place;

Fig. 7 is a view in perspective of one of the two wedge members withwhich each lining is provided, and whereby the several plates arewedgedly held against the inner surface of the grinding mill shell.

Referring specifically to the several vlews, the grinding mill shell 11is provided with my liner 12. The liner 12 is formed or composed of anumber of Separate lining plates 13, each of which is curved to conformto, or in accordance with, a curve which is traced by a point within agenerating circle which rolls, without sliding, within a larger basecircle. This curve is known as the trochoid, sometimes called thehypotrochoid, and belongs to that class of second degree curves known asthe cycloidal family. As the mill is rotated, the ingredients thereofpartake of a motion similar to the motion of the generating circle, bywhich the curvature of the lining plates was constructed, and this localagitation and forward movement, as well aS the local rotation of each ofthe cylpebs or balls, causes the contents of the mill to be efiicientlyground, the entire action taking place without sliding, and thereforewith a minimum amount of wear upon the lining plates. In order to causethe ingredients to break over, similar to the surf of the ocean waves,and in order to break up any particular formation within the mill, theadjacent trochoidal arcs, or more specifically the adjacenthypotrochoidal arcs, are formed from different generating circles, sothat while they still are trochoidal' in form they are of different wavelengths and amplitudes; thus the trochoidal arc AB in Fig. 2 is ofgreater wave length and amplitude than the adjoining trochoidal arc BX.

In order that the various plates may be held in their proper positions,they are arranged to overlap, the toe end 15 at each plate beingprovided with the bolt openings 16, and the beveled under surface 17.top surface 18 of the heel end of the plate is correspondingly beveledso as to nicely receive the beveled toe end of the next adjacent platethereon: Suitable slots 19 are formed in the heel end of the plate andin connection with the bolt openings 16 of the adjacent plate, areadapted to receive the holding bolts 20 therethrough, which latterextend through suitable openings in the mill shell andsecure the liningplates thereto.

The lining plates are provided. with the strengthening andlongitudinally extending ribs 21, which extend beneath, and are formedintegral with, the crest portion of the waves of. the plates, so as toreinforce and strengthen the plates against the severe hammering actionwhich they necessarily re- The ceive, and also materially reducing theelongation of the plates which is especially likely to take place whenthey are formed of manganese steel, the preferred metal for suchstructures.

A somewhat modified form of liner is illus trated in Fig. 5, wherein theends of the lining plates 24 do not overlap but are each provided withthe transversely extending ribs 26 which contact with the inner surfaceof the shell 25 and provide for the proper support of the lining plate.The ends of the lining plates, in addition to the ribs 26, include thetongues 27 which fit within and interlock with the grooves or recesses28 provided within the holding members 29. The holding members are ofH-shape so as to receive'the projecting tongues of adjacent liningplates therein and hold them against inward displacement.

Each complete lining is provided with two wedge members 29, and whichinclude the tapering sides 30, adapted to fit between,

and engage, the beveled ends 31, which areprovided upon four of thelining plates. Suitable bolts 32 extend through these wedge members anddraw them down toward the shell 25, and in so doing, force the liningplates into their interlocked positions with the holding members 29 andthus hold the various lining plates against the inner periphery of themill shell. As disclosed in Fig. 5, each lining is preferably formedwith two diametrically positioned wedge members, thus insuring theproper retention of the lining plates, even though they become somewhatelongated or distorted under the severe conditions under which theyoperate. A material saving in bolts will thus be effected in this mannerof securing the plates in position, and does not interfere with theagitation of the mass disposed within the mill which results in theefficient grinding thereof.

What I claim is 1. A lining plate for a grinding mill the workingsurface of which is wave-like or undulatory in form, and of tr'ochoidalshape in cross-section on a plane perpendicular to dicular to the axisof the said shell being trochoidal in form relative .to the innersurface thereof, so far as regards their respective working surfaces;andmeans for securing said plates in place within and upon the innersurface of said shell; the sucof San Francisco and State of California,cessive Waves or undulations provided by the this 12th day of April, A.D. 1915.

Working surfaces of said plates, collectively ALEXANDER V. JENSEN.considered, differing from one another in Witnesses: 5 Wave length andin amplitude. M. V. COLLINS,

Signed at San Francisco, in the county J. W. PLANT.

